Pruning spotty red tip photinia

Question

Moved into a home in August with a beautiful tall (25 ft) hedge of red tipped photinia. There are 9 plants, each plant base has about 4 feet space between it and the next and the tops are intertwined. Each base is crowded and should have been thinned as they were growing, trunks have merged, but previous owners have neglected these beautiful plants in my opinion. This spring it’s very apparent that it has a fungus. One has completely lost at least 80% of its leaves, each day more fall! This is the first year here. Will this one that’s 90% bare die? Should I go ahead and remove it? Should I attempt to prune the others now in hopes of thinning out the hedge? I’d love to save them all as it’s awesome privacy but honestly if I’d be sure to save even 1 of the nine I’d take out the rest! I’m really concerned they’re all going to die!! I know if you prune it forces new growth. And the new growth is the most susceptible. I know I should prune when dormant. If I prunein the middle of summer will it still force new growth? Ideally I’d like to clean up the bases to show off the nice trunks keep the top canopy. And keep like four of the bushes and let them keep growing with room the breathe. I think it’d still be enough privacy. I’m in north texas and these things are everywhere!!! Only mine are yellowing! Something is up!
Thank you sooo much!

Answer 1

Pruning will help, but you will need to address the infection as well. I would add wettable sulfur, and dolomitic lime to the area around each. This will kill off the pest, and recondition the soil back to a more suitable status. This article will help you in caring for these: https://www.google.com/url?q=https://www.gardeningknowhow.com/ornamental/shrubs/photinia/rejuvenating-red-tip-photinia.htm&sa=U&ved=0ahUKEwjT9Nyqp7_aAhWDvVMKHQG_CLIQFggIMAE&client=internal-uds-cse&cx=009296322515861343460:jftykenwinc&usg=AOvVaw3NlQ34ordt0_XKKBGJAg09